Rheostat for electric-motor cars



(No Model.) 2 Sheets-Sheet 1.

S. H. SHORT.

RHBOSTAT FOR ELECTRIC MOTOR CARS. No. 459,794. Patented Sept. 22, 1891.

(No Model.) 2 Sheets-Sheet 2.

S. H. SHORT. RHEOSTAT FOR ELECTRIC MOTOR CARS. No. 459,794. Patented Sept. 22,1891.

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UNITED STATES PATENT OFFICE.

SIDNEY II. SHORT, OF CLEVELAND, OHIO.

RHEOSTAT FOR ELECTRIC-MOTOR CARS.

SPECIFICATION forming part of Letters Patent No. 459,794, dated September 22, 1891.

Application filed March 17, 1891. Serial No. 385392. (No model.)

To all whom it may concern:

Be it known that I, SIDNEY II. SHORT, of Cleveland, in the county of Ouyahoga and State of Ohio,have invented certain newand usefulImprovementsin Adjustable Rheostats for Electric-Motor Cars; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates more particularly to the adj ustable rheostats or rheostatic-eurrent regulators used on electrically-propelled cars or Vehicles; but each of the improvements constituting said invention is included for all the uses to which it may be adapted.

Heretofore in motor-car rheostats it has been customary to have the contact-board in immediate connection with the resistances. This is objectionable because the sparking on the contactboard tends to heat the resistances, and also because the compactness of the apparatus tends to prevent free access of air. In accordance with the present invention the contact-board is separated from the resistances with which it is in electrical communication by suitable conductors, and the resistances or the contact-board, or both, are exposed to the air outside of the car-body, preferably under the same. Further, to increase the cooling effect a number of separate resistances are used,and also a fine arranged in the direction of the cars motion, in which or in the line of which one or more resistances are placed. With the arrangement of the rheostat outside of the car, whether an air duct or fine is used or not, the motion of the car produces an air-current over the exposed resistances of the rheostat, whereby the same is constantly cooled, not merely by radiation, but by actual convection of heat. The same effect is also produced upon the switch-board, which is similarly placed, and by reason of the separation of the rheostat from the switch-board both are prevented from heating each other and both are cooled separately and effectively.

The invention also comprises a special form of resistance comprising one or more of the following features: First, it is composed of an assemblage of plates (preferably resistance-plates of iron with insulating-plates interposed) with openings through the same, so placed as to register with one another and form air-spaces through the resistance; second, heat-conducting plates (preferably of a metal which is a good conductor of heat, like copper) are placed between the resistanceplates, beyond which they project; third, pencils of slate (or othersuitable non-conducting material) are inserted through holes in the plates which are clamped by bolts between end plates.

"The invention also comprises the particular constructions, combinations, and arrangements of parts, as hereinafter set forth.

In the accompanying drawings, which form part of this specification, Figure I is a partial view in longitudinal section of a car provided with an adjustable rheostat in accordance with the invention. Fig. II is a plan of said rheostat. Fig. III is a vertical section on line i ii of Fig. 11 of one of the resistances on a larger scale. Figs. IV and Y are plans of one of the resistance-plates and of one the insulating-plates, respectively; and Figs. VI, VII, and VIII are views showing in detail the manner of assembling the plates of a resistance. 4

The contact-board consists of a non-conducting base A, a series of contacts 2, a switcir ing-arm B, which travels over said contacts, and means of operating said switching-arm in the form of a sprocket-wheel C, fast on the shaft of said arm. The contact-board is sup ported by the hanger-rods 3 from the under side of the car and is separate from the re sistances. It is exposed to the air, so that the contacts will be kept cool.

The resistances D to D inclusive, are separated from the contact-board and are in electrical comi'nunication with the contacts 2 through the conductors a to 16, inclusive. They are exposed to the air under the carbody. As shown, they are each composed of an assemblage of plates, as hereinafter more particularly described, and four of them are double. They are suspended under the carbody by means of the hanger-rods 17, which uphold the wooden side bars 18, the metallic eross-bars 19 to 22, inclusive, and the resistances arranged by twos on said cross-bars.

The resistances are connected with each other in series in the following manner: The

resistances D and D rest upon and are electrically connected at the bottom by the crossbar 1.). The resistances D and D are electrically connected at the top by the wire 23. The resistances D and D are electrically connected at the bottom by the cross-bar 20, on which they rest. The resistances D and D are electrically connected at the top by the wire 24. The resistances D and Dare electrically connected at the bottom by the crossbar 21, on which they rest. The resistances D and D are electrically connected at the top by the wire 25. The resistances D and D are electrically connected at the bottom by the cross-bar 2 on which they rest. The

conductor 4 from the first of the contacts 2 runs to the top of the resistance D, the conductor 5 from the second contact to the cross-bar 19, the conductor 6 to the top of resistance D the conductor 7 to cross-bar 20, the conductor 8 to the top of resistance D, the conductor 9 to the middle of resistance D the conductor 10 to the cross-bar 21, the conductor 11 to the middle of resistance D, the conductor 12 to the top of resistance D the conductor 13 to the middle of resistance D the conductor 14 to cross-bar 22, the conductor 15 to the middle of the resistance D, and the conductor 16 to the top of the resistance D. By turning the switch-arm B, therefore, more or less of the resistances are included in the circuit between the conductor 27, which connects with the first of the contacts 2, and the conductor 28, which connects with the switching-arm B. To make a strong draft over the resistances and at the same time to protect the resistances from dirt, they are inclosed in a flue E, composed of a sheetmetal trough fastened to the bottom of the car by the hangers 29 and open at both ends.

The general arrangement just described or one or more of the features of such arrangement which are claimed herein as being within the invention which it is desired to secure by Letters Patent maybe used with resistances of various forms or constructions. It is specially designed, however, to use resistances composed of an assemblage of plates with perforations through the same for pen mitting an interior circulation of air, and also with heat-conducting plates projecting beyond to assist in conducting away the heat from the interior of the resistance to the air which flows over the projecting margins of the heat-conducting plates. As shown, each resistance is composed of the resistance-plates a, of, say, wrought-iron, theinsulating-plates b, of, say, mica or asbestos, the heat-conducting plates 0,01, say, copper, the clampingplates (1 (Z, of, say, bronze, the non-conducting pencils 6, of, say, slate, and the clamp ing-bolts f, of, say, wrought-iron or steel. The resistances D and D also have electrodeplates g. All the plates, including the heads (I d, are slotted or perforated. The resistance-plates a have slots 30, which extend alternately from opposite edges, so as to form each plate into a sort of coil. The insulating-plates, the heatconducting plates, and the electrode-plates each have slots or perforations 31, and the heads are made with pcrforations 32. \Vhen the plates are assembled, these slots or perforations register with each other and form air-passages. The insulatingplates are slit at 33, so that the adjacent perforated end can he slipped over the perforated end of a resistance-plate, as shown in Figs. VI and VII, the remaining portion of the 1nsulating-plate lying on the opposite side of the resistance-plate. One or more insulatingplates may be thus arranged relatively to each resistance-plate, or two or more plates can be arranged as shown in Fig. VII.

In assembling the plates they are strung on the pencils e, and the resistance-plates are so turned that they are in contact with each other alternately at opposite ends, as shown in Fig. VIII. I11 the upper part of this figure the insulating-plates are arranged according to Fig. VI and in the lower part according to Fig. VII. At suitable intervals the heat-conducting plates 0 are interposed, and one or more electrode-plates g may also be introduced. The heads (Z d are larger than the intermediate plates, and are clamped together by the insulated bolts f, which are out of contact with the intermec'liate plates. The heads are provided with sockets 34, which receive the ends of the pencils 6. The cross-bars 19 to 22 are provided with perforations 35, and also with holes 36, to receive the sockets 011 the bottom of the heads (1' and binding-posts 37 for the conductors from the contact-board. The heads (Z each have binding-posts 88.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination, with an electric-motor car and an exposed rheostat located outside of the car in an open flue or air-duct running lengthwise the car-body, of a switch-board also located outside of the car and separated from the rheostat, electric connect-ions be tween the rheostat and switch-board, and operating mechanism for the latter within convenient reach of the motor-1nan, substantially as described.

2. The combination, with an electric-motor car and an exposed rheostat located under the car-body in an open flue running lengthwise of the said car-body, of a switch-board also located under the car-body and separated from the rheostat, electric connections between the rheostat and switch-board, and operating mechanism for the latter within convenient reach of the motor-man, substantially as described.

3. A rheostatic element composed of a series of plates with laminae of insulating material between them, said plates and insulating laminze having openings through the same, forming interior air-spaces, substantially as described.

t. A resistance comprising an assemblage of plates strung on non-conducting pencils and clamped between heads or end plates,

' conducting pencils between said heads, and

resistance-plates and insulating-plates strung on the pencils and clamped between the heads, substantially as described.

6. A rheostatic element comprising clamping-heads, clamping-bolts for the same, resistance-plates and insulating-plates alternatin g with the same, and heat-conducting plates, all clamped between the said heads, substantially as described.

7. .A rheostatic element comprising, in combination socketed heads, non-conductin g pencils fitted in said sockets, and resistanceplates strung on said pencils, substantially as described.

8. The resistances comprising each an as semblage of resistance plates, insulatingplates, and heat-conducting plates, in combination with means to support the same under the car-body, so as to be exposed to the air, and a separate contact-board, substantially as described.

9. A rheostatic element comprising the slot ted resistance-plates, the perforated or slotted insulating-plates between the resistanceplates, the perforated or slotted heat-conducting plates introduced at intervals between the resistance plates, and the perforated heads for binding or clamping the plates together, substantially as described.

I11 testimony whereof I have signed this specification in the presence of two subscribing witnesses.

SIDNEY H. SHORT. Vitnesses:

E. H. MoRRIsoN, A. B. CALHOUN. 

